Chapter 3 Hardware Overview
AT-MIO/AI E Series User Manual 3-12
National Instruments Corporation

Figure 3-7. Dither

You cannot disable dither on the AT-MIO-16XE-10, AT-AI-16XE-10,

or AT-MIO-16XE-50. This is because the resolution of the ADC is so

fine that the ADC and the PGIA inherently produce almost 0.5 LSB rms

of noise. This is equivalent to having a dither circuit that is always

enabled.

Multiple-Channel Scanning Considerations

All of the AT E Series boards can scan multiple channels at the same

maximum rate as their single-channel rate; however, you should pay

careful attention to the settling times for each of the boards. The

settling time for most of the AT E Series boards is independent of the

selected gain, even at the maximum sampling rate. The settling time for

the high channel count and very high-speed boards is gain dependent,

which can affect the useful sampling rate for a given gain. No extra

settling time is necessary between channels as long as the gain is

100 200 300 4000 500
-4.0
-2.0
0.0
2.0
4.0
-6.0
LSBs
LSBs
LSBs
LSBs
6.0
100 200 300 4000 500
-4.0
-2.0
0.0
2.0
4.0
-6.0
6.0
100 200 300 4000 500
-4.0
-2.0
0.0
2.0
4.0
-6.0
6.0
100 200 300 4000 500
-4.0
-2.0
0.0
2.0
4.0
-6.0
6.0

a. Dither disabled; no averaging b. Dither disabled; average of 50 acquisitions

c. Dither enabled; no averaging

100 200 300 4000 500
-4.0
-2.0
0.0
2.0
4.0
-6.0

d. Dither enabled; average of 50 acquisitions

LSBs
LSBs
LSBs
LSBs
6.0
100 200 300 4000 500
-4.0
-2.0
0.0
2.0
4.0
-6.0
6.0
100 200 300 4000 500
-4.0
-2.0
0.0
2.0
4.0
-6.0
6.0
100 200 300 4000 500
-4.0
-2.0
0.0
2.0
4.0
-6.0
6.0